The present invention generally relates to methods and equipment for cutting food products. More particularly, this invention relates to apparatuses equipped with at least one knife suitable for cutting food product slices, wherein the knife is tensioned so as to be sufficiently rigid to slice a food product, for example, a potato.
Various types of equipment are known for slicing, shredding and granulating food products, such as vegetable, fruit, dairy, and meat products. A widely used line of machines for this purpose is commercially available from Urschel Laboratories, Inc., under the name Urschel Model CC®, an embodiment of which is represented in FIG. 1. The Model CC® machine line provides versions of centrifugal-type slicers capable of producing uniform slices, strip cuts, shreds and granulations of a wide variety of food products at high production capacities.
FIGS. 2 and 3 are perspective views of an impeller 10 and cutting head 12, respectively, of types that can be used in the Model CC® machine of FIG. 1. In operation, the impeller 10 is coaxially mounted within the cutting head 12, which is generally annular-shaped with cutting knives 14 mounted on its perimeter. The impeller 10 rotates within the cutting head 12, while the latter remains stationary. Each knife 14 projects radially inward toward the impeller 10 in a direction generally opposite the direction of rotation of the impeller 10, and defines a cutting edge at its radially innermost extremity. As represented in FIG. 2, the impeller 10 has generally radially-oriented paddles 16 with faces that engage and direct food products (e.g., potatoes) radially outward against the knives 14 of the cutting head 12 as the impeller 10 rotates.
FIG. 1 schematically represents the cutting head 12 mounted on a support ring 28 above a gear box 30. A housing 32 contains a shaft coupled to the gear box 30, through which the impeller 10 (not shown) is driven within the cutting wheel 12. Further descriptions pertaining to the construction and operation of Model CC® machines are contained in U.S. Pat. Nos. 5,694,824 and 6,968,765, the entire contents of which are incorporated herein by reference.
The cutting head 12 shown in FIG. 3 comprises a lower support ring 18, an upper support ring 20, and circumferentially-spaced support segments (shoes) 22. The knives 14 of the cutting head 12 are individually secured with clamping assemblies 26 to the shoes 22. Each clamping assembly 26 includes a knife holder 26A mounted to the radially inward-facing side of a shoe 22, and a clamp 26B mounted on the radially outward-facing side of a shoe 22 to secure the knife 14 to the knife holder 26A. The shoes 22 are represented as being secured with bolts 25 to the support rings 18 and 20. The shoes 22 are equipped with coaxial pivot pins (not shown) that engage holes in the support rings 18 and 20. By pivoting on its pins, the orientation of a shoe 22 can be adjusted to alter the radial location of the cutting edge of its knife 14 with respect to the axis of the cutting head 12, thereby controlling the thickness of the sliced food product. As an example, adjustment can be achieved with an adjusting screw and/or pin 24 located circumferentially behind the pivot pins. FIG. 3 further shows optional gate insert strips 23 mounted to each shoe 22, which the food product crosses prior to encountering the knife 14 mounted to the succeeding shoe 22.
The knives 14 shown in FIG. 3 are depicted as having straight cutting edges for producing flat slices, though other shapes are also used to produce sliced and shredded products. For example, the knives 14 can have cutting edges that define a periodic pattern of peaks and valleys when viewed edgewise. The periodic pattern can be characterized by sharp peaks and valleys, or a more corrugated or sinusoidal shape characterized by more rounded peaks and valleys when viewed edgewise. If the peaks and valleys of each knife 14 are aligned with those of the preceding knife 14, slices are produced in which each peak on one surface of a slice corresponds to a valley on the opposite surface of the slice, such that the slices are substantially uniform in thickness but have a cross-sectional shape that is characterized by sharp peaks and valleys (AV-slices@) or a more corrugated or sinusoidal shape (crinkle slices), collectively referred to herein as periodic shapes. Alternatively, shredded food product can be produced if each peak of each knife 14 is aligned with a valley of the preceding knife 14, and waffle/lattice-cut food product can be produced by intentionally making off-axis alignment cuts with a periodic-shaped knife, for example, by cross-cutting a food product at two different angles, typically ninety degrees apart. Whether a sliced, shredded or waffle-cut product is desired will depend on the intended use of the product.
Equipment currently available for cutting food product, such as those represented in FIGS. 1-3, are well suited for producing slices of a wide variety of food products. Even so, further improvements are desirable, particularly if capable of improving the quality of a food product. For example, it is often desirable to reduce levels of surface cracking, through-slice cracking, and surface roughness of sliced, shredded, and waffle-cut food products. As a particular example, if a sliced, shredded, or waffle-cut food product is intended for chips, for example, potato chips, surface cracks can undesirably lead to increased oil consumption, damaged starch cells, yield loss (starch does not stay in the chip), etc.